Method and system for displaying icons representing information items stored in a database

ABSTRACT

Methods and apparatus are provided for accessing an experience journal which includes unstructured text items relating to a topic, such as a medical condition. The method is implemented in a computer system including a processor, a storage device, a video display unit having a display screen, and a user interface. The unstructured text items are stored in the storage device. Similarities among the unstructured text items are determined, and icons, one corresponding to each of the unstructured text items, are displayed on the display screen. The icons are positioned on the display screen relative to each other, such that the distances between icons are representative of the determined similarities among the unstructured text items. In response to user selection of one of the icons, the corresponding unstructured text item is displayed on the display screen.

FIELD OF THE INVENTION

This invention relates to methods and apparatus for providingcomputerized access to an experience journal containing unstructuredtext items relating to a topic and, more particularly, to a computerizedexperience journal wherein text items are automatically arrangedaccording to similarity and wherein text items of interest can beaccessed with extreme ease.

BACKGROUND OF THE INVENTION

Medical advances make it increasingly possible for children withpreviously fatal illness to live and thrive. However, a significantnumber still experience repeated operations, hospitalizations andinvasive procedures, or need special care at home. Many do so withlittle or no intervention to help them and their families cope with theemotional stresses involved. Serious medical illness is, therefore,increasingly recognized as an important early risk factor for emotionaldisturbance.

A variety of interventions have been developed to assist patients andtheir families with the hope of improving the resiliency of both. Theseinclude pre-admission hospital preparatory programs, meetings betweenfamilies and physicians, books and videos for children of different agesand psychiatric consultation. Yet it is clear that the majority offamilies are not able to avail themselves of these resources beforecoming to the hospital.

One additional and potentially underutilized source of psychologicalsupport is the community of patients and families who have experiencedhospitalization. However, in spite of a general willingness to shareexperiences, communication among patients and families is usuallylimited. To facilitate this process, the use of computer technology torecord, organize and display stories about the experiences of familieswith children who have been treated for serious illness has beenproposed. Children and their families are asked to record text andmultimedia vignettes describing some aspect of their illness, copingstrategies or care that might be useful to others. The collection oftext and vignettes is referred to as an experience journal.

A difficulty arises in providing access to the items in the experiencejournal. The text items are highly unstructured and differ greatly instyle, content and sophistication. The items may be prepared by anyonefrom a physician or a parent to a young child. Thus, organizing the textitems for access is extremely difficult. The user group likewise mayvary from medical professionals to parents to very young children. Thus,the text items must be available to users with limited computer skills.Because the text items are unstructured and differ greatly in content,existing techniques of index, classification and search are not useful.Accordingly, there is a need for methods and apparatus for organizingand providing access to an experience journal which includesunstructured text items relating to a topic.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, methods and apparatus forproviding access to an experience journal including unstructured textitems relating to a topic are provided. The method is implemented in acomputer system comprising a processor, a storage device, a videodisplay unit having a display screen, and a user interface. The computersystem executes the steps of storing the unstructured text items in thestorage device, determining similarity among the unstructured text itemsand displaying icons, one corresponding to each of the unstructured textitems on the display screen. The icons are positioned on the displayscreen relative to each other such that the distances between icons arerepresentative of the determined similarities among the unstructuredtext items. In response to user selection of one of the icons, thecorresponding unstructured text item is displayed on the display screen.

The similarity among the unstructured text items may be determined byanalyzing the unstructured text items for use of the same words. Inparticular, stop words may be removed from the text items and suffixesmay be removed from words in the text items. The remaining words in thetext items are weighted according to the inverse of their occurrencefrequency in a reference text to provide a word vector for each of thetext items. A similarity score is determined for each pair ofunstructured text items by determining the dot product of thecorresponding word vectors.

The icons are preferably positioned relative to each other bymultidimensional scaling of the determined similarities among theunstructured text items.

A new text item may be entered into the experience journal afteroptional review and editing by a screening committee by determiningsimilarity between the new text item and other text items in theexperience journal, displaying a new icon corresponding to the new textitem on the display screen and positioning the new icon relative toother icons such that the distances between the icons are representativeof the determined similarities among the text items.

The experience journal may be implemented as a website on the World WideWeb. Alternatively, the experience journal may be implemented on a localarea network, on a single computer or on a combination of the World WideWeb and one or more local area networks. The principal user functionsinclude accessing entries in the experience journal and submitting newentries for inclusion in the experience journal.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, reference is madeto the accompanying drawings, which are incorporated herein by referenceand in which:

FIG. 1 is a block diagram of a computer system suitable for implementingthe present invention;

FIG. 2 is a block diagram of a computer network suitable forimplementing the present invention;

FIG. 3 is a flow chart of the operation of an experience journal inaccordance with an embodiment of the invention;

FIG. 4 is a flow chart of an example of a process for determiningsimilarity between text items shown in FIG. 3;

FIG. 5 is a flow chart of an example of a process for determining iconpositions shown in FIG. 3;

FIG. 6 illustrates an example of a welcome display window that may beused in the experience journal;

FIG. 7 illustrates an example of an icon display window containing iconsthat represent text items in the experience journal;

FIG. 8 illustrates an example of a display window for entry of a textitem into the experience journal; and

FIG. 9 illustrates an example of a display window for control of theexperience journal by a screening committee.

DETAILED DESCRIPTION

FIG. 1 is a block diagram of an example of a computer system that may beused in implementing the present invention. A central processing unit(CPU) 10 is connected to a memory 12 that stores instructions to beexecuted by the CPU 10. The memory 12 can be any type of memory,including RAM, ROM, CD ROM, magnetic disk, hard disk, etc. Data relatingto execution of the instructions may also be stored in the memory 12.Alternatively, different memories can be used for the instructions andthe data. The CPU 10 is also connected to a video display unit 16 fordisplaying information to a user. The user can input information to theCPU through a user interface including a keyboard 20 and a pointingdevice 22, such as a mouse or a trackball. A network interface 24connected to CPU 10 may be used to interface the computer system to alocal area network (LAN) or a wide area network (WAN), such as the WorldWide Web. It will be understood that the computer system may have avariety of different components, configurations and capabilities withinthe scope of the present invention.

A computer network suitable for implementation of the present inventionis shown in FIG. 2. Computers 30, 32, . . . 38 are interconnected on anetwork 40 which may be a LAN, the World Wide Web or a combination of aLAN and the World Wide Web. One of the computers, such as computer 30,may be designated as a website for the computerized experience journalof the invention. The computer 30 may be used for control of theexperience journal by a screening committee as described below. Theremaining computers may access text entries in the experience journalthrough network 40 and may submit new text items for inclusion in theexperience journal.

One purpose of the invention is to provide a way for a community togather, organize and share the community's collective wisdom on a giventopic or issue in an experience journal. In one example, the communityincludes the families of children who have been through a cardiac unitat a hospital. Families can contribute to the experience journal bysubmitting personal narratives about their experiences, helpfulinformation, poems and stories, as well as pictures and video about theexperience of coping with a serious illness.

One feature of such personal narratives is that they are quite unlikethe logically structured and uniform text that is found in media such asencyclopedia articles and newspaper stories. In general, the personalnarratives may be considered unstructured, anecdotal text. Much of theaccepted wisdom about text-based information retrieval has beendeveloped for more structured text data. For example, in structured textdata, researchers have found that specification of an indexing or aclassification scheme can be useful. However, in an experience journal,it may be difficult to predict the topics that contributors will want toaddress, and restricting contributions to a predefined set of topics isan unacceptable constraint.

Another key distinction is that an experience journal should lend itselfto browsing. The type and degree of organization needed to supporteffective browsing is very different from that which is needed tosupport effective querying. Therefore, the fundamental operation in anexperience journal tends not be “find an entry with the followingkeywords”, so much as “find an entry that is related to the one I justread” or “find an entry that is very different from the one I justread”.

An important characteristic of an experience journal is that it willgrow and evolve continuously over time, even while people are readingit. For this reason, a preset limit on the size of an experience journalis unacceptable. Furthermore, contributors will hope to see an entryincluded within the experience journal soon after writing it. Therefore,a model wherein successive experience journal versions are produced andreleased at intervals may be undesirable.

Contributions to an experience journal will come from many individualsin many styles and forms. In order to make authoring and submission aseasy as possible, minimal assumptions are made about the form of anexperience journal entry.

Websites that contain experience journal data can be organized andmaintained by a human webmaster. However, sufficient funds to pay aprofessional webmaster may not be available. Accordingly, the experiencejournal should be self-organizing and self-evolving, and should becapable of operating indefinitely without supervision or intervention byspecifically trained people.

In addition to being able to browse an experience journal within ahospital, participating families should be able to access it over theInternet, using a variety of different web browsers. Furthermore, userswith only the basic computer skills should be able to browse anexperience journal. For this reason, the interface to the experiencejournal preferably uses simple point and click actions rather than moresophisticated access and browsing models, such as Boolean queries ortailored databases.

A flow chart of the operation of the experience journal in accordancewith the invention is shown in FIG. 3. Major functions available to theuser include submission of text items for inclusion in the experiencejournal and access to text items in the experience journal. A particularuser may be involved with either or both functions.

A text item for entry into the experience journal can be a HTML document(created with Netscape Navigator Gold or Microsoft Front Page, forexample), an ASCII text file or a URL for either type of file. After itis composed by a contributing patient or family in step 100, a text itemfor the experience journal may be communicated by e-mail to the membersof a screening committee, which may be composed of members of thehospital staff and parents of present and former patients. The task ofthe committee is to review the submitted text entry in step 102 todetermine whether the text item should be entered into the experiencejournal as submitted or whether it should be edited to eliminatematerial that could be medically harmful or legally compromising. Thetext item may be edited as necessary. When committee acceptance isgiven, the text item is then translated automatically into HTML format,if necessary, and is incorporated into the experience journal in step104.

The relationship of the new entry to existing experience journal entriesmust be established. In step 106, the similarity among the text items inthe experience journal is determined. The similarity between each pairof text items is quantified as a similarity score as described in detailbelow in connection with FIG. 4. The similarity scores are used in step108 to determine icon positions in a display window. In particular, eachtext item in the experience journal is represented by an icon 110 in adisplay window 116, as shown in FIG. 7. The icons are positioned in thedisplay window 116 relative to each other, such that the distancesbetween the icons are representative of the determined similaritiesamong the text items. Thus, for example with reference to FIG. 7, icons112 and 114 represent text items that have a high degree of similarity,whereas icons 110 and 112 represent text items that have a relativelylow degree of similarity. A preferred technique for determining iconpositions is described below in connection with FIG. 5. After the iconpositions have been determined, the icon display window 116 is generatedin step 120. As indicated above, the positions of the icons in thedisplay are indicative of similarity. Thus, groups of icons correspondto similar text items in the experience journal.

The experience journal is then available for access by users. In step122, the process waits for user selection of an icon, typically bypointing and clicking with pointing device 22 (FIG. 1). In step 124, adetermination is made as to whether a user selection has been made. Whena user selection has not been made, the process continues to wait instep 122. When a user selection is made, the text item corresponding tothe selected icon is displayed in step 130. As shown in FIG. 7, aselected text item 132 is displayed in a text window 136 in the leftside of the display screen. An icon 134 corresponding to the text item132 may be highlighted for reference by the user in selecting similar ordissimilar text items.

A flowchart of an example of a process for determining similarity amongtext items in the experience journal is shown in FIG. 4. In step 200,stop words are removed from each text entry. Stop words, such as “the”,“and”, “is”, etc., are those words which occur with such high frequencyin the text as to be useless for determining similarity in meaningbetween text items. In step 202 suffixes, such as “ly”, “ing”, etc., arestripped from the words in the text items. In step 204, the remainingwords in each text item are weighted according to the inverse of theiroccurrence frequency in a large reference text. Thus, rarely used wordsare weighted heavily, and commonly used words are discounted. Theweights for each text item are represented as a word vector. Asimilarity score for a pair of text items is determined in step 206 asthe dot product of the word vectors associated with the two text items.The procedure of FIG. 4 is repeated for each pair of text items in theexperience journal, thus providing measures of similarity among all thetext items in the experience journal. Techniques for determiningsimilarity between texts based on similarity scores are described by G.Salton in Automatic Text Processing: The Transformation. Analysis andRetrieval of Information by Computer, Reading, MA: Addison-Wesley, 1989,chapters 8-10.

The similarity scores for the pairs of text items in the experiencejournal are used to determine the positions of the icons in the displaywindow 116. The technique of multidimensional scaling may be used toposition icons so that similar entries in the experience journal arelocated near each other in the display window and dissimilar entries arelocated far apart. Thus, proximity rather than coordinate location isthe measure of similarity. Clusters of similar entries form naturally.Techniques for multidimensional scaling are described by I. Borg et alin Modern Multidimensional Scaling: Theory and Applications, Berlin:Springer, 1997 and by J. B. Kruskal in “Multidimensional Scaling andOther Methods for Discovering Structure”, Statistical Methods forDigital Computers, Englein, Ralston, Wilf (eds.), vol. 3, Wiley, pages296-335.

A flow chart of the process for determining icon positions on thedisplay screen is shown in FIG. 5. The similarity scores, or“distances”, are obtained from the process of FIG. 4 in step 250. Pointscorresponding to the text items are embedded in a multidimensional spacein step 252 such that all pairs of points are the desired distances fromeach other. In step 254, the points are projected onto a two-dimensionalspace in which these distances are best preserved. The icons aredisplayed in step 256 using their corresponding point positions in thetwo-dimensional space.

Given any pairwise distance measures between points, it is possible toembed the points in some Euclidean space such that the points are therequired distances from each other. This is due to a theorem by Youngand Householder. If this space is two-dimensional, then we could use thepoint coordinates in the space as the coordinates for the screen displayof the icons. However, this is rarely the case; usually the Euclideanspace in which the points are embedded has very high dimensionality. Inorder to use this embedding to inform the display layout, it isnecessary to project the points from the multi-dimensional Euclideanspace to a two-dimensional Euclidean space. There are of course aninfinite number of ways to do this projection. We would like to find theprojection that best preserves the distances between points. Thisprojection is found by using Principal Component Analysis. The principalcomponent is any vector such that the perpendicular projections of thepoints from the multi-dimensional space in which they were embedded ontothat vector have the largest possible variance. The secondprincipal-component vector is any vector orthogonal to the first, suchthat the perpendicular projections of the points onto it have thelargest possible variance. The first two principal-component vectorstherefore define a desired two-dimensional Euclidean space, i.e., onethat preserves the interpoint distances. In fact, it can be proved thatthe two-dimensional Euclidean space defined by the principal-componentvectors is the best two-dimensional space for preserving thesedistances. Once the points have been projected onto this two-dimensionalspace, the point coordinates can be used as the locations of thecorresponding icons in the screen display.

Examples of display screens that may be utilized in implementing thecomputerized experience journal of the present invention are shown inFIGS. 6-9. An example of a welcome display is shown in FIG. 6. A welcomedisplay window 300 includes a pond 302 having lilypad icons 304 and afrog icon 306. By pointing and clicking on various components of thewelcome display window 300, different informational messages are givento the user. Menu buttons at the top of the display may be used forselecting other windows in the experience journal. A button 310 is usedfor selecting the welcome display window 300. A button 312 is used forselecting a “read” display as shown in FIG. 7. A button 314 is used forselecting a “write” display as shown in FIG. 8.

The read display, an example of which is shown in FIG. 7, is used foraccessing and reading text items in the experience journal. The icondisplay window 116 includes icons, such as lily pad icons 110, 112, 114,etc., distributed in a background area, such as a pond 332. As discussedabove, each of the icons corresponds to one of the text items in theexperience journal. Distances between icons in display window 116 arerepresentative of similarity between the corresponding text items. Thus,icons are closely spaced when the corresponding text items arerelatively similar, and icons are widely spaced when corresponding textitems are relatively dissimilar. The read display further includes textwindow 136 for displaying a selected text item, such as text item 132.The corresponding icon 134 may be highlighted in the icon displaywindow. A new text item may be selected by pointing to one of the iconsand clicking the pointing device. The user may select similar text itemsby selecting icons that are clustered together and may select dissimilartext items by selecting icons that are widely spaced.

Additional optional features may be included in the read display. Forexample, the icon display window 116 may indicate the age of text itemsin the experience journal. In particular, the intensity of the icons mayindicate the time from acceptance into the experience journal. Newertext items are represented by relatively intense icons, whereas oldertext items are represented by less intense, faded icons. An iconrepresentative of a particular text item is initially intense followingacceptance and fades with time toward the background color. The iconsnever disappear entirely but instead reach a minimum intensity level.The aging of the display may be accomplished by attaching a time stampindicative of the time of acceptance to each text item. The intensity ofthe corresponding icon is based on a difference between the present timeand the time of acceptance. It will be understood that displayparameters other than intensity may be utilized to indicate the ages ofthe text items.

In another example of an optional feature, the icon display window 116may indicate a trail of text items selected by the user. The trail maybe indicated, for example, by icons of a selected color, withsuccessively reduced brightness indicating less recently accessed textitems. The selected color is different from the color of text items thathave not been selected by the user.

An additional optional feature is the ability to magnify a portion ofthe icon display window 116. Magnification buttons 350, 352, 354, etc.may be provided at the top of the display screen. Differentmagnification buttons provide different magnification factors. When oneof the magnification buttons 350, 352, 354, etc. is selected, amagnified region 360 appears in icon window 116. Within magnified region360, the distances between icons are magnified to facilitate selectionof a text item. The magnification feature is useful in the case ofclusters of icons which represent similar text items. The magnifiedregion 360 may be moved in the icon window 116 using the pointingdevice. A button 370 is used to establish a view at normal scale withoutmagnification.

An additional optional feature is associated with icons 380, 382, 384,etc. positioned below icon window 116. Icons 380, 382, 384 representlinked text items in the experience journal. The text items may belinked according to similarity or according to another criteria. Byselecting one of the icons 380, 382, 384 etc., the corresponding linkedtext item is accessed and is displayed in text window 136.

The experience journal icon display window has been described asincluding lilypad icons on a pond background. It will be understood thatany suitable icons and any suitable background may be utilized withinthe scope of the present invention. Different backgrounds, such as forexample a cityscape or a sunset, may be utilized as appropriate for aparticular application of the experience journal. Furthermore, thebuttons on the experience journal display may be changed to providedifferent options and functions as necessary for a particularapplication.

An example of a write display for adding text items to the experiencejournal is shown in FIG. 8. The user enters a narrative text, with fewif any restrictions, using keyboard 20 (FIG. 1). After the text item iscompleted to the satisfaction of the user, it can be submitted to theexperience journal for review and editing by the review board byselecting button 400. This causes the new text item to be sent on thenetwork to the control computer 30 (FIG. 2). Conventional text entryfunctions may be provided in the write display. In the example of FIG.8, the write display includes a new document button 410, an opendocument button 412, a save button 414, a save copy button 416, a printbutton 418, a cut button 420, a copy button 422 and a paste button 424.A button 430 may provide access to an administrative display, an exampleof which is shown in FIG. 9 and described below. A password may berequired for access to the administrative display.

An example of an administrative display used by the screening committeein the control computer is shown in FIG. 9. An “included” window 500shows a list of text items previously included in the experience journalby title. A “submitted” window 502 indicates text items submitted byusers for entry into the experience journal but not yet reviewed by thescreening committee. A “hold” window 504 lists text items that have beensubmitted but which have been placed on hold for further review and/orediting. A “text” window 510 displays a selected text item from one ofthe windows 500, 502 or 504. The text item in window 510 may be editedby the screening committee to eliminate material that can be medicallyharmful or legally compromising to the hospital or other organization.When the text item is accepted by the screening committee, it may beincluded in the experience journal by selecting button 520. Thus, button520 causes a selected text item to be transferred from submitted window502 to included window 500. The processes described above fordetermining similarity between the new text item and the other textitems in the experience journal and for positioning an icon in the iconwindow are executed. A new icon corresponding to the newly entered textitem then appears in the icon window. The new text item is thenavailable for selection by users in the read display.

Additional function buttons on the administrative display include abutton 522 for transferring a text item from hold window 504 tosubmitted window 502. A button 524 transfers a selected text item fromsubmitted window 502 to hold window 504. A button 530 selects a dialogbox that may be used to access a different experience journal or tocreate a new experience journal. Button 530 is used in connection withsystems that may provide access to more than one experience journal.

The experience journal has been described thus far in connection amedical application wherein the experience journal contains stories andother narratives relating to an illness. However, the experience journalmay be utilized in any situation where a community wishes to shareunstructured information relating to a particular topic or issue. Theexperience journal is particularly useful where the entries areunrestricted as to style, content and form and where the experiencejournal may be accessed by users having very limited computer skills. Insome applications, the screening committee, which edits and acceptsentries in the experience journal, may be unnecessary. In this case,newly submitted text items are included directly in the experiencejournal without editing or review. Likewise, in some applications,states of the experience journal may be fixed for periodic distribution.

Having thus described certain embodiments of the present invention,various alterations, modifications, and improvements will readily occurto those skilled in the art. Such alterations, modifications, andimprovements are intended to be within the spirit and scope of theinvention. Accordingly, the foregoing description is by way of exampleonly, and not intended to be limiting. The invention is limited only asdefined in the following claims and the equivalents thereof.

What is claimed is:
 1. A method for displaying icons representing information items stored in a database, comprising the steps of: determining similarity between each of a plurality of information items in a database and every other one of the plurality of information items in the database; and displaying a plurality of icons, each icon corresponding to a respective one of the plurality of information items in the database, on a display screen such that the determined similarity between each information item in the database and every other information item in the database is represented by a position of each of the displayed plurality of icons.
 2. The method of claim 1, wherein determining similarity between each of the plurality of information items and every other one of the plurality of information items comprises the step of: determining a similarity score between each of the plurality of information items and every other one of the plurality of information items.
 3. The method of claim 2, wherein positioning the plurality of icons comprises the steps of: embedding points corresponding to each of the plurality of information items in a multidimensional space such that pairs of points are spaced by distances representative of the similarity score for the corresponding pair of information items; projecting the points onto a two-dimensional space in which the distances between the points are preserved; and displaying the plurality of corresponding icons using their corresponding point positions in the two-dimensional space.
 4. The method of claim 1, wherein positioning the plurality of icons includes multidimensional scaling of the determined similarities among the plurality of information items.
 5. The method of claim 1, further comprising the steps of: linking similar one of the plurality of information items; and indicating the linked ones of the plurality of information items by marking the corresponding ones of the plurality of icons on the display screen.
 6. The method of claim 1, wherein: each of the plurality of information items is associated with a vector; and determining similarity between each of the plurality of information items in the database and every other one of the plurality of information items in the database includes comparing each of the associated vectors with every other one of the associated vectors.
 7. The method of claim 1, wherein: each of the plurality of information items is associated with a vector; and determining similarity between each of the plurality of information items in the database and every other one of the plurality of information items in the database includes computing the dot product of each of the associated vectors with every other one of the associated vectors.
 8. A method for displaying icons representing information items stored in a database, comprising the steps of: determining similarity between each of a plurality of information items in a database and every other one of the plurality of information items in the database; and displaying a plurality of icons, each icon corresponding to a respective one of the plurality of information items in the database, on a display screen such that the determined similarity between each information item in the database and every other information item in the database is represented by a position of each of the displayed plurality of icons; wherein displaying the plurality of icons includes indicating a relative age of each of the corresponding information items relative to each of the other information items.
 9. The method of claim 8, wherein indicating relative ages of information items includes varying a parameter of the corresponding icon in accordance with the age of the corresponding information item.
 10. A method for displaying icons representing information items stored in a database, comprising the steps of: determining similarity between each of a plurality of information items in a database and every other one of the plurality of information items in the database; displaying a plurality of icons, each icon corresponding to a respective one of the plurality of information items in the database, on a display screen such that the determined similarity between each information item in the database and every other information item in the database is represented by a position of each of the displayed plurality of icons; determining similarity between a new information item and each of the plurality of information items; and displaying a new icon corresponding to the new information item such that the position of the new icon relative to each of the plurality of icons represents the determined similarities among the plurality of information items and the new information item.
 11. Apparatus for providing access to an experience journal including unstructured text items relating to a topic, said apparatus comprising: a computer system including a processor, a storage device, a video display unit having a display screen, and a user interface, said computer system further comprising: means for storing the unstructured text items in the storage device; means for determining similarity among the unstructured text items; means for displaying icons, one corresponding to each of the unstructured text items, on the display screen, including means for positioning said icons relative to each other such that the distances between said icons are representative of the determined similarities among the unstructured text items; and means responsive to user selection of one of said icons for displaying the corresponding unstructured text item on the display screen.
 12. The apparatus of claim 11, wherein the means for determining similarity comprises a processor configured to: determine a similarity score between each of the plurality of unstructured text items and every other one of the plurality of unstructured text items by determining the dot product of corresponding word vectors of each of the plurality of unstructured text items and every other one of the plurality of unstructured text items to determine similarity among the plurality of unstructured text items.
 13. The apparatus of claim 12, wherein the means for positioning the icons comprises a video display unit configured to: embed points corresponding to the plurality of unstructured text items in a multidimensional space such that pairs of points are spaced by distances representative of the similarity score for the corresponding pair of unstructured text items; project the points onto a two-dimensional space in which the distances between said points are preserved; and display the plurality of associated icons using their corresponding point positions in the two-dimensional space to position the plurality of associated icons.
 14. The apparatus of claim 11, wherein the means for displaying the icons comprises a video display unit configured to: display the plurality of icons with an indication of the relative age of each of the corresponding unstructured text items relative to every other one of the plurality of unstructured text items in the experience journal.
 15. The apparatus of claim 11, wherein the means for positioning the icons comprises a video display unit configured to: multidimensionally scale the determined similarities among the plurality of unstructured text items to position the plurality of icons.
 16. The apparatus of claim 11, further comprising: a processor configured to link similar ones of the plurality of unstructured text items; and a video display unit configured to indicate the linked ones of the plurality of unstructured text items by marking the corresponding icons on the display screen.
 17. A system for determining similarity between information items, comprising: a processor configured to generate a plurality of vectors, each of the plurality of vectors based upon information contained in a corresponding one of a plurality of information items, and to determine similarity between each of the plurality of information items and every other one of the plurality of information items based upon the generated plurality of vectors; and a storage device configured to store the plurality of information items, the plurality of vectors, and the results of determining similarity between each of the plurality of information items and every other one of the plurality of information items based upon the generated plurality of vectors.
 18. The system of claim 17, wherein: the processor is further configured to compare each of the plurality of vectors with every other one of the plurality of vectors to determine similarity between each of the plurality of information items and every other one of the plurality of information items; and wherein the storage device is further configured to store the results of the comparison of each of the plurality of vectors with every other one of the plurality of vectors.
 19. The system of claim 17, wherein: the processor is further configured to compute a plurality of dot products, each dot product being the dot product of each of the plurality of vectors with every other one of the plurality of vectors, to determine similarity between each of the plurality of information items and every other one of the plurality of information items; and wherein the storage device is further configured to store the computed plurality of dot products.
 20. A system for maintaining a database, comprising: an expandable storage device configured to store a plurality of data items having a determined relationship; an input device for adding a new data item to the system; and a processor configured to determine a relationship between the new data item and each of the plurality of stored data items and to add the new data item to the storage device.
 21. A method for maintaining a database, comprising the steps of: receiving a new data item; processing the new data item to determine a relationship between the new data item and each of a plurality of data items having previously determined relationships; and storing the new data item in a storage device containing the plurality of data items. 